The Senate stood up Thursday for the honor of America’s top commander in Iraq – with a few notable exceptions. New York Sens. Hillary Clinton and Chuck Schumer among them.

The vote was 72-25 on a resolution to “strongly condemn personal attacks on the honor and integrity of Gen. Petraeus and all members of the United States Armed Forces.”

Supporting such a resolution would seem like a no-brainer – especially for someone like Clinton, who’s asking voters to trust her as commander-in-chief.

Unfortunately for her, the attacks in question come from the influential far-left activist machine of MoveOn.org, which recently took out a full-page ad in The New York Times calling Petraeus a liar and a traitor.

It was a baseless smear against a brave and honorable soldier, and Clinton should have said so from the start.

Why didn’t she? Let’s just say that MoveOn isn’t the kind of group you want to cross when you’re trying to win Democratic primaries.

Other Dem White House hopefuls faced a similar dilemma. Sen. Chris Dodd (D-Conn.) also voted against the resolution; Barack Obama (D-Ill.) and Joe Biden (D-Del.) were two of the three senators to skip the vote.

How pathetic.

Schumer is chairman of the Democratic Senatorial Campaign Committee, which raises funds for Democratic candidates in Senate races. No surprise, then, that he’s not about to cross MoveOn’s powerful donor base.

The Dems’ public line, of course, is that the resolution itself was a distraction from the serious business of the Senate.

But it’s MoveOn’s influence within the Senate’s majority party that makes the ad such a grave matter in the first place.

MoveOn, after all, is no dime-a-dozen fringe outfit. With 3.2 million members and deep pockets, it famously boasted after the 2006 election that it had just “bought” the Democratic Party.

So when such a group calls a man who’s risked his life and career for the American people “General Betray Us,” Senate Democrats have a duty to respond.

That neither Clinton, Schumer nor any of the Democratic presidential contenders could bring themselves to do that is a disgrace.